Testing of torpedoes and the training of crews usually require launches of test and practice vehicles to determine their effectiveness. After a run is completed, the vehicle, usually a torpedo, is buoyed to the surface and a torpedo recovery boat retrieves it for study and reuse. Because no simple current limiting solution is available, conventional weight release devices have had reliability problems since the electro-mechanical relays tend to be underrated for high current applications. The additional problems of contact corrosion and mechanical failure are inherent in electro-mechanical relays and cannot be completely eliminated without eliminating the relays.
Thus, a continuing need exists in the state of the art for a reliable control circuit for releasing a weight which is not susceptible to false triggering by spurious signals nor has the limitations normally associated with electro-mechanical relays.